Transmission gear position detection method and device

Abstract

The invention relates to a gear position detection method of a vehicle transmission. The method includes determining a fork position of a shift fork from a first position sensor; when it is judged that the first position sensor indicates that the shifting fork is located at the non-neutral gear position, a first transmission ratio and a second transmission ratio are compared, the first transmission ratio is determined by the first position sensor, and the second transmission ratio is determined through the input shaft rotating speed and the output shaft rotating speed of the transmission; and when it is judged that the first transmission ratio is inconsistent with the second transmission ratio, a gear error processing sub-process is entered.

Description

Technical Field

[0001] The present application relates to vehicle shift control, and in particular to a gear position detection method and device for a vehicle transmission. Background Art

[0002] For an automatic mechanical transmission (AMT), the automation of gear shifting requires that the vehicle can accurately identify the current gear position, thereby avoiding gear shift failure or malfunction and improving vehicle driving safety. In existing solutions, the gear position is determined by directly detecting the linear displacement of the shift fork as part of the shift actuator. Summary of the invention

[0003] Unreliable identification of the gear position of a vehicle transmission may cause unexpected acceleration or deceleration of the vehicle, or even cause a traffic accident. The solution provided in this application aims to improve the reliability of identification of the gear position of a transmission.

[0004] According to a first aspect of the present application, a gear position detection method for a vehicle transmission is disclosed. The method includes determining a shift fork position of a shift fork from a first position sensor; when it is determined that the first position sensor indicates that the shift fork is in a non-neutral position, comparing a first transmission ratio and a second transmission ratio, wherein the first transmission ratio is determined by the first position sensor and the second transmission ratio is determined by the input shaft speed and the output shaft speed of the transmission; when it is determined that the first transmission ratio is inconsistent with the second transmission ratio, entering a gear error handling sub-process.

[0005] In one or more embodiments of the first aspect of the present application, optionally, when it is determined that the first position sensor indicates that the shift fork is in a neutral position, the position of a transmission component of the shift actuator is determined by a second position sensor, and when it is determined that the position of the transmission component of the shift actuator determined by the second position sensor indicates that the shift fork is in a non-neutral position, the gear error handling sub-process is entered.

[0006] In one or more embodiments of the first aspect of the present application, optionally, the transmission component of the shift actuator includes a shift cam, and when the second position sensor indicates that the angle of the shift cam is outside a predetermined range, it is determined that the shift fork is in a non-neutral position.

[0007] In one or more embodiments of the first aspect of the present application, optionally, the second position sensor is an angle sensor arranged relative to the axle of the shift cam.

[0008] In one or more embodiments of the first aspect of the present application, optionally, the second position sensor is a Hall sensor for detecting the rotor angle of the shift motor, and the process of determining the angle of the shift cam includes converting the rotor angle into the angle of the shift cam.

[0009] According to a second aspect of the present application, a transmission controller is disclosed, which includes a processor and a memory, wherein the memory stores computer program instructions, and when the computer program instructions are executed by the processor, the processor can perform one or more steps of the method according to the first aspect of the present application.

[0010] According to a third aspect of the present application, a computer program product for gear detection is provided. When the computer program instructions are executed by a processor, the processor is enabled to perform one or more steps of the method described in the first aspect of the present application.

[0011] According to a fourth aspect of the present application, a computer-readable storage medium for gear detection is provided, and when the instructions are executed by a processor, the processor is enabled to perform one or more steps in the method described in the first aspect of the present application.

[0012] The inventor of the present application has noticed the reliability problem of gear position detection in the prior art and has designed different additional detection schemes for different gear positions (engaged or neutral) to improve the reliability of gear position detection, which helps to improve the safety of vehicle driving. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The principles, features and advantages of the present invention will be more fully understood by referring to the following detailed description of specific exemplary embodiments in conjunction with the accompanying drawings.

[0014] Figure 1 is a block diagram of a vehicle shift control system according to an embodiment of the present application.

[0015] Figure 2 It is a schematic diagram of a vehicle shift control process according to an embodiment of the present application.

[0016] Figure 3A This is a flow chart of transmission gear position detection according to one embodiment of the present application.

[0017] Figure 3B This is a flow chart of transmission gear position detection according to another embodiment of the present application.

[0018] Figure 4 is a flow chart of a gear cross-check performed by a transmission controller according to one embodiment of the present application.

[0019] Figure 5is a block diagram of a transmission controller according to one embodiment of the present application. DETAILED DESCRIPTION

[0020] In order to make the technical problems, technical solutions and beneficial technical effects to be solved by the present invention clearer, the present invention will be further described in detail in conjunction with the accompanying drawings and multiple exemplary embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the scope of protection of the present invention. Those skilled in the art will easily recognize that the same principles can be applied to other systems different from the vehicle shift control system described herein, and these same or similar principles can be implemented therein, and any such changes do not deviate from the spirit and scope of the present application.

[0021] Figure 1 FIG. 1 is a block diagram of a vehicle shift control system according to an embodiment of the present application. Figure 1 As shown, the shift control system 10, i.e., the transmission system 10, includes a transmission controller 11 and a shift actuator 12. The transmission controller 11 can be electrically connected to the shift actuator 12. The transmission controller 11 can control the shift actuator 12 to switch gears according to, for example, a vehicle speed signal, an accelerator pedal signal, etc., and a shift strategy stored in the transmission controller 11.

[0022] The transmission controller 11 and the vehicle controller 20 can be communicatively coupled via a CAN bus. For example, the transmission controller 11 can send a shift request to the vehicle controller 20, and receive a shift permission instruction from the vehicle controller 20. In addition, those skilled in the art can understand that the vehicle controller 20 can send signals such as the desired driving mode, the desired wheel end torque, the accelerator pedal position, and the brake pedal position to the transmission controller 11, and the transmission controller 11 can send signals such as the actual driving mode, the actual wheel end torque, and the actual gear information to the vehicle controller 20.

[0023] The transmission controller 11 and the drive motor controller 31 may be communicatively coupled via a CAN bus. The interaction between the transmission controller 11 and the drive motor controller 31 may include the transmission controller 11 sending a desired motor operation mode and a desired motor speed, etc. to the drive motor controller 31, and the drive motor controller 31 sending an actual motor operation mode and an actual motor speed, etc. to the transmission controller 11. The drive motor controller 31 is electrically connected to the motor 32 to control the operation of the motor 32. The motor 32 is mechanically coupled to the gears in the gearbox, so that the drive torque of the motor 32 is transmitted to the wheel end of the vehicle through the gear set.

[0024] The shift actuator 12 may include a shift motor, a transmission component, and a shift fork. Figure 1As shown in FIG. 1 , those skilled in the art will appreciate that the rotation output of the shift motor can be converted into the movement of the shift fork by the arrangement of the transmission component. The transmission component and the shift fork can have various suitable structures and cooperate with each other.

[0025] The transmission controller 11 can be driven by a shift motor driver ( Figure 1 The shift motor of the shift actuator 12 is controlled by a control device (not shown) to start and stop and rotate speed. The output end of the shift motor and the transmission component cooperate to convert the rotation output by the shift motor into the axial movement of the shift fork in the direction of the input shaft of the transmission system. The axial movement of the shift fork can push the shift sleeve or synchronizer to make the shift gear engage or disengage with the transmission gear, thereby achieving gear engagement or disengagement. The shift fork pushes the shift sleeve or synchronizer to engage with different transmission gears to form different transmission ratios, thereby achieving gear switching. In one or more embodiments of the present application, the position of the shift fork is determined by detecting the position of the shift fork at the start or end of the axial movement in different ways.

[0026] Figure 2 It is a schematic diagram of a vehicle shift control process according to an embodiment of the present application. Figure 2 The various stages 201 to 206 of the gear shift are schematically shown. In this embodiment, an electrically driven two-speed automatic transmission is taken as an example to briefly describe the gear shift process and exemplarily specify the timing for determining the gear position.

[0027] Phase 201 is a shift request phase, in which the transmission controller determines whether to shift gears based on signals such as the current vehicle speed signal, the accelerator pedal signal, the brake pedal signal, and the shift strategy stored in the transmission controller. When the transmission controller determines that the shift condition is met, it sends a shift request to the vehicle controller, and enters phase 202 in response to the shift permission command from the vehicle controller.

[0028] In stage 202 , the transmission controller sends a torque unloading instruction to the drive motor controller to reduce the output torque of the drive motor to zero.

[0029] After the torque unloading is completed, in stage 203, the transmission controller performs the shifting operation. In this stage, the transmission controller controls the shift motor, and the shift motor drives the shift fork to move axially in the direction of the input shaft of the transmission system and pushes the shift sleeve to separate from the transmission gear. In this process, the transmission controller monitors the position of the shift fork to determine whether the shift fork is in the neutral position. When the transmission controller determines that the shift fork is in the neutral position, the transmission controller stops driving the shift motor. The transmission controller can determine the gear position by various shift fork position sensors. In one or more embodiments of the present application, additional methods of detecting the position of the shift fork are described.

[0030] In stage 204 , the transmission controller sends a target speed signal to the drive motor controller, which adjusts the motor speed accordingly to control the speed difference between the synchronizing side and the synchronized side, so as to prepare for the gear shifting operation in stage 205 .

[0031] In stage 205, after the drive motor controller completes the speed regulation, the transmission controller drives the shift motor again to drive the shift fork to push the shift gear sleeve to engage with the transmission gear. During the gear shifting process, the transmission controller monitors the position of the shift fork to determine whether the shift fork is in the target gear position.

[0032] In stage 206 , after the gear shifting is completed, the transmission controller sends a torque recovery request and the target torque to the drive motor controller according to the target torque from the vehicle controller.

[0033] In the above-mentioned vehicle shift control process, it is necessary to monitor the position of the shift fork to determine the gear position. As mentioned above, in the known method, the gear position is determined only by detecting the linear displacement of the position of the shift fork. When the position sensor for the shift fork fails or the detected displacement value is near the critical value, the judgment of the gear position may be unreliable. One or more embodiments of the present application provide the use of additional methods to cross-check the gear position, improve the reliability of the gear position detection, and thus improve the safety of vehicle driving.

[0034] Figure 3A This is a flow chart of the transmission gear position detection according to an embodiment of the present application. In the gear shifting process of this embodiment, the gear position is cross-checked in consideration of the vehicle's drivability and vehicle driving safety. As mentioned above, in the known method, the gear position is determined by detecting the linear displacement of the position of the shift fork by a position sensor. In this embodiment, the gear position is checked in consideration of the input shaft speed and the output shaft speed.

[0035] The process of transmission gear position detection starts from step 301 .

[0036] In step 302, the gear transmission ratio, i.e., the first transmission ratio, is determined by the fork position sensor. The fork position sensor is a position sensor arranged relative to the shift fork itself. The position sensor may be a sensor based on magnetism, optics, or inductance. In one example, the position sensor may be arranged on the fork shaft of the shift fork to detect the swing angle of the fork shaft. In this example, the position sensor is a Hall sensor. The magnetic field signal obtained by induction may be converted into a PWM signal by the Hall principle. It will be appreciated by those skilled in the art that the duty cycle of the PWM signal may be converted into the displacement distance of the end of the fork arm by calibration or conversion. The transmission ratio may be determined from the position-gear mapping table according to the fork position indicated by the fork position sensor. For example, when the fork position is in the range of [-4.5, 4.5] mm, the gear is determined to be neutral; when the fork position is in the range of [-8.5, -4.5], the gear is determined to be first gear; when the fork position is in the range of [4.5, 8.5], the gear is determined to be second gear. The shift fork position here refers to the position of the end of the shift fork arm of the shift fork.

[0037] In step 303, it is determined whether the fork position sensor indicates that the fork position is in the neutral gear position. If yes, the method proceeds to step 307 to end, otherwise it proceeds to step 304A.

[0038] In step 304A, a reference transmission ratio, i.e., a second transmission ratio, is determined. Those skilled in the art will appreciate that the second transmission ratio is obtained by the ratio of the input shaft speed to the output shaft speed. The input shaft speed and the output shaft speed can be obtained by a speed sensor installed at the shaft end.

[0039] Then, in step 305A, the transmission ratio determined by the fork position sensor is compared with the second transmission ratio determined by the input shaft speed and the output shaft speed. When the two are consistent, the process proceeds to step 307 and ends, otherwise it proceeds to step 306.

[0040] In step 306, the gear error handling sub-process is entered. That is, when it is determined that the transmission ratio determined by the fork position sensor is inconsistent with the second transmission ratio determined by the input shaft speed and the output shaft speed, it is determined that the current gear position information is unreliable, and the fault handling procedure is entered. The fault handling procedure can, for example, restart the vehicle, interrupt the torque transmission of the vehicle to make the vehicle drive slowly, or trigger the vehicle braking process. In the gear error handling sub-process of this embodiment, a zero torque request is sent to the drive motor controller of the vehicle.

[0041] Figure 3B This is a flow chart of transmission gear position detection according to another embodiment of the present application. Figure 3A In the embodiment of FIG. 1 , when it is determined that the fork position sensor indicates that the fork position is in the neutral gear position, the method proceeds to step 307 and ends. Figure 3A The embodiment in the embodiment is different in that the fork position sensor indicates that the fork position is in the neutral gear position, and the fork position sensor also checks the fork position, thereby covering the inspection of all gear position conditions. Different from checking the gear position in a non-neutral position by the input shaft speed and the output shaft speed, the embodiment checks the gear position in the neutral position by detecting the position of the transmission component of the shift actuator.

[0042] The process of transmission gear position detection starts from step 301 .

[0043] The gear ratio is determined by the fork position sensor in step 302. The gear ratio is determined from a position-gear mapping table according to the fork position indicated by the fork position sensor.

[0044] In step 303, it is determined whether the fork position sensor indicates that the fork position is in the neutral gear position. If yes, the method proceeds to step 304B, otherwise proceeds to step 304A.

[0045] In step 304B, another position sensor is used to detect the position of the transmission component of the shift actuator. As mentioned above, the shift actuator may include a shift motor, a shift transmission component and a shift fork. The transmission controller controls the start and stop and speed of the shift motor through the shift motor driver. The rotational output of the shift motor can be converted into the movement of the shift fork through the arrangement of the transmission component. The transmission component and the shift fork can have various suitable structures and cooperate with each other. Those skilled in the art can understand that the configured transmission component can transmit the rotation of the output shaft of the shift motor to the fork shaft of the shift fork, and the swing of the fork shaft drives the movement of the end of the fork arm, so that the shift fork pushes the shift gear sleeve to engage with the transmission gear or separate from the transmission gear through the movement of its end to achieve gear engagement or gear disengagement.

[0046] In one example, the transmission component includes a shift cam. When another position sensor indicates that the angle of the shift cam is outside a predetermined range, it is determined that the shift fork is in a non-neutral position. Those skilled in the art will appreciate that the shift motor can drive the shift cam to rotate via a gear, and through the cooperation between the cam groove and the shift fork, the shift cam can cause the end of the shift fork arm to be displaced while rotating. Because the angular range of the shift cam corresponds to the gear position, the other position sensor can be an angle sensor disposed relative to the axle of the shift cam. The rotation angle range of the shift cam detected by the angle sensor can indirectly determine whether the shift fork is in a neutral position. The duty cycle, angle range, and whether the PWM signal of the angle sensor of the shift cam is in a neutral position can be calibrated.

[0047] In another variant, the other position sensor may be a Hall sensor for detecting the rotor angle of the shift motor. It is understood that the rotation angle of the shift cam can be obtained by the transmission ratio of the mechanical transmission design from the output shaft of the shift motor to the shift cam. The absolute angle of the shift cam can be obtained based on the initial angle of the shift cam and the relative angle of the current shift cam obtained by the Hall sensor.

[0048] In step 305B, when it is determined that the position of the transmission component of the shift actuator determined by the other position sensor indicates that the shift fork is in a non-neutral position, the gear error processing sub-process of step 306 is entered.

[0049] In the gear error handling subroutine of step 306 , a zero torque request is sent to a drive motor controller of the vehicle.

[0050] In the above embodiment, by arranging the position sensor relative to the transmission component, the monitoring accuracy of the gear position can be improved, and the arrangement of the position of the sensor for gear position monitoring can be optimized. The double detection of whether the gear is in neutral can also avoid accidents caused by the failure of a single position sensor in extreme cases.

[0051] Figure 4 is a flow chart of a gear cross-check performed by a transmission controller according to one embodiment of the present application. The transmission controller may be as follows Figure 1 The transmission controller 11 is described.

[0052] like Figure 4 As shown, the gear cross-check method executed by the transmission controller includes steps 401 to 430 .

[0053] In step 410, the fork position of the shift fork is determined from the first position sensor. Those skilled in the art will appreciate that the first position sensor may be any suitable sensor capable of detecting the fork position of the shift fork.

[0054] In step 420, the fork position of the shift fork determined from the first position sensor is cross-checked to improve the accuracy of gear recognition, thereby improving the safety of vehicle driving. Different from the prior art, in this embodiment, the first position sensor indicates that the gear is in a neutral position and a non-neutral position (for example, 1st gear and 2nd gear) to check, thereby covering all situations of the gear position. The gear position can be cross-checked at any appropriate time. In one example, the gear position is cross-checked during the gear switching process (including processes such as disengaging and engaging gears). In another example, the gear position is cross-checked when the vehicle is powered on or during the driving of the vehicle.

[0055] In step 420, two checking methods are specifically used to respectively deal with the situation when the first position sensor indicates that the shift fork is in a non-neutral position and the situation when the first position sensor indicates that the shift fork is in a neutral position.

[0056] When it is determined that the first position sensor indicates that the shift fork is in a non-neutral position, the transmission ratio determined by the first position sensor is compared with the second transmission ratio determined by the input shaft speed and the output shaft speed of the transmission. When it is determined that the transmission ratio determined by the first position sensor is inconsistent with the second transmission ratio, step 430 is entered, i.e., the gear error handling sub-process.

[0057] When it is determined that the first position sensor indicates that the shift fork is in the neutral position, the position of the transmission component of the shift actuator is determined by the second position sensor. When it is determined that the position of the transmission component of the shift actuator determined by the second position sensor indicates that the shift fork is in the non-neutral position, step 430 is entered, i.e., the gear error handling sub-process.

[0058] In one example, the transmission component of the shift actuator includes a shift cam, and when the second position sensor indicates that the angle of the shift cam is outside a predetermined range, it is determined that the shift fork is in a non-neutral position. The second position sensor is an angle sensor arranged relative to the axle of the shift cam.

[0059] In another example, the second position sensor is a Hall sensor that detects a rotor angle of the shift motor, and the process of determining the angle of the shift cam includes converting the rotor angle into the angle of the shift cam.

[0060] In yet another example, the first position sensor is a Hall sensor disposed relative to a fork shaft of the shift fork, and determining the fork position of the shift fork includes converting a rotation of the fork shaft into a linear movement of an end of a fork arm of the shift fork.

[0061] In step 430, the gear error handling sub-process may include sending a zero torque request to the vehicle's drive motor controller. When the cross-check fails, the current transmission ratio is unreliable, which may easily cause unexpected acceleration of the vehicle. At this time, the transmission controller can control the vehicle to enter a relatively safe state. Those skilled in the art will understand that for cross-check failures, other gear error handling sub-processes may be set to eliminate safety hazards as soon as possible. In other examples, the transmission controller may notify the vehicle controller of a cross-check failure signal, and the vehicle controller may prompt the fault information through the vehicle human-computer interaction interface.

[0062] Figure 4The process of the gear cross check performed by the transmission controller can be implemented by one or more software functional units in the transmission controller. The division of functional units is a logical function division, and there may be other division methods when implementing it. Multiple units and devices can be physically separated or distributed on network units, which can be combined or integrated into another system.

[0063] Figure 2-4 Each step of the flowchart in the figure can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer or other programmable data processing device to form a machine, so as to execute these instructions by the processor of the computer or other programmable data processing device. In some alternative implementations, the steps shown in the box may not occur in the order shown in the flowchart. For example, the two boxes shown in sequence can actually be executed substantially simultaneously or in different orders.

[0064] Figure 5 FIG. 5 is a block diagram of a transmission controller according to an embodiment of the present application. The vehicle transmission controller 500 is used to implement, for example, Figure 1 The control operation of the transmission controller 11 in the embodiment of the present invention is applied to Figure 2-4 The control method shown. The transmission controller 500 may include a processor 510 and a memory 520. The processor 510 and the memory 520 communicate via a bus, or may communicate via other means such as wireless transmission. The memory 520 is used to store instructions, and the processor 510 is used to execute the instructions stored in the memory 520. The memory 520 may include a read-only memory (ROM) and a random access memory (RAM). The processor 510 may call the program code stored in the memory 520 to execute multiple steps of the method described above. The transmission controller 500 also includes Figure 5 The transmission controller 500 communicates with various vehicle electronic components via an input / output (I / O) interface. The computer program code stored in the memory 520 is loaded into the memory and then executed by the processor 510.

[0065] One or more of the above embodiments, one or more examples, can be implemented in whole or in part by software, hardware or a combination thereof. When implemented using software, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes computer program instructions, which can be downloaded to the memory of the controller via a computer network, or can be transmitted to the memory of the controller in a wired manner. When the computer program instructions are executed by the processor of the controller, the processor is enabled to perform one or more steps of the method described herein. The computer program instructions can be provided in a computer-readable storage medium. The computer-readable storage medium referred to herein can be any available medium that can be accessed by a general-purpose or special-purpose computer.

[0066] The above description is only a specific embodiment of the present application, and the protection scope of the present application is not limited thereto. Those skilled in the art can think of other feasible changes or substitutions based on the technical content and teachings disclosed in the present application, and such changes or substitutions are all included in the protection scope of the present application. Where appropriate, the embodiments of the present application and the features of the embodiments may be combined with each other. The protection scope of the present application shall be subject to the description of the claims.

Claims

1. A method for detecting the gear position of a vehicle transmission, characterized in that: include: determining a fork position of a shift fork from a first position sensor; When it is determined that the first position sensor indicates that the shift fork is in a non-neutral position, comparing a first gear ratio and a second gear ratio, the first gear ratio being determined by the first position sensor and the second gear ratio being determined by an input shaft speed and an output shaft speed of the transmission; When it is determined that the first transmission ratio is inconsistent with the second transmission ratio, the gear error processing sub-process is entered.

2. The method according to claim 1, characterized in that: Also includes: When it is determined that the first position sensor indicates that the shift fork is in the neutral position, the position of the transmission component of the shift actuator is determined by the second position sensor, When it is determined that the position of the transmission component of the shift actuator determined by the second position sensor indicates that the shift fork is in a non-neutral position, the gear error processing sub-process is entered.

3. The method according to claim 2, characterized in that: The transmission component of the shift actuator includes a shift cam, and when the second position sensor indicates that the angle of the shift cam is outside a predetermined range, it is determined that the shift fork is in a non-neutral position.

4. The method according to claim 3, characterized in that: The second position sensor is an angle sensor disposed relative to the axle of the shift cam.

5. The method according to claim 3, characterized in that: The second position sensor is a Hall sensor for detecting the rotor angle of the gear shift motor. The process of determining the angle of the shift cam includes converting the rotor angle to the angle of the shift cam.

6. The method according to claim 1, characterized in that: The first position sensor is a Hall sensor arranged relative to the fork shaft of the shift fork. The process of determining the fork position of the shift fork includes converting the rotation of the fork shaft into a linear movement of the end of the fork arm of the shift fork.

7. The method according to claim 1, characterized in that: The gear error handling sub-routine includes sending a zero torque request to a drive motor controller of the vehicle.

8. A transmission controller, characterized in that: The controller comprises a processor and a memory, wherein the memory stores computer program instructions, and when the computer program instructions are executed by the processor, the processor is capable of performing the method according to any one of claims 1-7.

9. A computer program product comprising computer program instructions, wherein: When the computer program instructions are executed by a processor, the processor is enabled to perform the method according to any one of claims 1 to 7.

10. A computer-readable storage medium, wherein instructions are stored in the computer-readable storage medium, characterized in that: When the instructions are executed by a processor, the processor is enabled to perform the method according to any one of claims 1 to 7.

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